Liquid ejecting device



April 1932- c. s. KlLE LIQUID EJECTING DEVICE Filed May 28. 1930 naw um Vw 6410mm Patented Apr. 5, 1932 UNITED STAT CLIFFORD S. KILE, OF HUTCHINSON, KANSAS LIQUID EJEGTING DEVICE Application filed. May 28,

The invention relates to a new and improved device for ejecting liquid in small measured quantities, being designed primarily for use by dentists to supply the proper amount of acid or other liquid to a predetermined quantity of cement powder for mixing to the proper consistency.

The deivce is of a general type in which a cartridge of liquid is placed in a tubular shell which is provided with a plunger for advancing a piston plug in the cartridge to expel the liquid through a tubular needle, the prinicpal object of the invention being to provide a unique and advantageous adjustable stop for controlling the forward movement of the plunger so that any required amount of liquid may be ejected.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawings.

Fig. 1 is a side elevation showing the cartridge started into the shell.

Fig. 2 is a vertical longitudinal sectional view showing the rear end of the cartridge engaged with the spring-pressed abutment and illustrating the front end of said cartridge in readiness for engagement with the fixed cartridge-holding abutment when said cartridge is moved slightly rearward with respect to the shell.

Fig. 3 is a longitudinal sectional view similar to Fig. 2 but illustrating the cartridge completely within the shell, the tubular needle inserted through the plug at the front end of said cartridge, and the piston plug partly projected by the plunger.

Figs. 4 and 5 are vertical transverse sectional views on lines 44 and 55 of Fig. 1.

A construction which has proven to be very advantageous and desirable from all standpoints, is herein disclosed. The descriptive matter will be directed rather specifically to this embodiment of the invention, but atten- 1930. Serial No. 456,708.

ing finger pieces 10 are rigidly joined.

Spaced somewhat in advance of the plug 9, is an annular rearwardly facing shoulder 11 formed in the shell 6, said shoulder normally abutting a similar but forwardly facing shoulder 12 on a cylindrical rear abutment 13 which is slidably mounted in the rear end of the shell. A coiled compression spring 14: is provided for normally advancing the abutment plug 13 to the limit allowed by the shoulders 11 and 12, said spring being preferably soldered or otherwise secured to said plug 13. The rear end of this spring abuts the plug 9.

From a point slightly in advance of the plug 13, entirely to the wall 7 the shell 6 is provided with a side entrance slot 15 through which a tubular cartridge 16 of liquid may be quickly and easily inserted. The space between the front end of the abutment plug 13 and the rear side of the abutment wall 7, is normally somewhat less than the length of the cartridge 16 as clearly shown in Fig. 2. Thus, when the cartridge is partially inserted through the slot 15 and disposed in contact with the plug 13, it is necessary to rearwardly shift said cartridge to some extent, the springpressed abutment 13 moving rearwardly during such shifting. Then, the cartridge may be swung about the abument 13 as a pivot, so that its front end also is within the shell 6. When the cartridge is thus within the shell, spring 14: is under tension and this tension causes firm holding of the cartridge between the 7two relatively movable abutments 13 and The cartridge 16 is of a known type whose front end is closed by a plug 17 of rubber or the like. The rear portion of the cartridge contains a piston plug 18 which is also usually formed from rubber. Friction between the plug 17 and the abutment wall 7 assists in holding the cartridge in the shell.

The piston plug 18 may be advanced in the cartridge 16 by means of a plunger 19. This plunger is in the form of a rod passing slidably through openings 20 and 21 in the plugs or collars 9 and 13, the member 9 being preferably provided with a key 22 engaging a longitudinal groove 23 in the plunger rod 19, thereby preventing rotation of the rod with respect to the remainder of the device. The front end of rod 19 is provided with an enlargement 24; to engage and advance the piston plug 18, and the rear end of said rod 19 is provided with a removable knob 25. Slidable along the rear portion of rod 19, is a collar 26 having a key 27 slidable in the groove 23. Pivoted upon this collar is a member 28 having a lateral thumb-piece 29 and a forwardly projecting arm 30, the latter having a detent 31 which may be engaged with any of a plurality of sockets 32 in the rod 19. By engaging the detent 31 with one or another of the sockets 32, engaging the first and second fingers with the finger pieces 10, engaging the thumb with the thumb piece 29 and by means of the latter forwardly forcing the rod 19, this rod advances the piston plug 18 to discharge the required amount of liquid through a tubular needle 33. This needle is provided with an appropriate finger-piece 3-1 and is not inserted through the plug 17 until its use is required. A ter such use, the needle is withdrawn and the needle formed opening in the plug 17 immediately seals, again hermetically sealing the cartridge 16.

It will be seen from the above that a rather simple and inexpensive, yet an eiiicient and very desirable instrument has been provided. Particular attention is invited to the member 28 and associated features of construction for advancing the plunger rod 19 and limiting such advance, also constitute important features of the invention.

Attention is again invited to the fact that within the scope of the invention as claimed, numerous variations may be made.

I claim 1. In a liquid ejector embodying a barrel, and a plunger rod extending into said barrel; a collar slidable along said rod, shoulders spaced apart along said rod, and a combined thrust-receiving and stop member pivoted to said collar, said member having a thrust-receiving portion projecting laterally from said rod and another portion extending longitudinally of said rod, the latter portion having a detent to engage any of said shoulders.

2. In a. liquid ejector embodying a barrel, and aplunger rod extending into said barrel;

a collar slidable upon said rod, shoulders spaced apart along said rod, a thumb-piece projecting laterally from said collar, means mounting said thumb-piece on said collar for movement forwardly and rearwardly with respect to the collar in a direction longitudinally of said rod, and a stop member adapted for engagement with any of said shoulders to hold the collar in desired position upon the plunger rod, said thumb-piece and stop memher being so connected that forward pushing upon said thumb-piece to operate said plunger rod, holds said stop member in operative position.

In testimony whereof I afliX my signature.

CLIFFORD S. KILE. 

